Semiconductors are very important products necessary in various industries, and a semiconductor chip is produced, for example, by slicing a silicon monocrystal into a predetermined thickness to manufacture a silicon wafer, and then forming plural integrated circuits etc. on this silicon wafer.
In the manufacturing process of this semiconductor chip, the silicon wafer put on an electrostatic chuck is subjected to various treatments such as etching and CVD, to form a conductor circuit, an element and so on. A resin for a resist is applied thereto and is then heated and dried.
For such heating, a ceramic heater is used. JP Kokai Hei 11-40330 and so on disclose a ceramic heater in which a substrate made of a carbide ceramic or a nitride ceramic is used and resistance heating elements are formed on the face opposite to a heating face of this ceramic heater (referred to as the bottom face hereinafter).